Abstract

Rasopathies are genetic disorders characterized by an alteration in RAS/MAPK signaling pathway. Such dysfunction gives place to syndromes with overlapping clinical manifestations where café-au-lait spots are a common manifestation. Legius syndrome previously known as neurofibromatosis type 1-like syndrome share the cutaneous manifestations with NF1 by the presence of  café-au-lait spots but it deffers in the absence of skin and central nervous system tumors that are observed in NF1. Children with sporadic manifestations of café-au-lait spots without other associated manifestations require molecular analysis of the NF1 and SPRED 1 genes to differentiate these two entities. Reach a diagnosis in patients with café-au-lait spots is a challenge due to the fact that this manifestations are therefore not pathognomonic and can also be present in other diseases and are insufficient for definitive diagnosis in the early years of life. It is important to have a comprehensive approach to these patients, including family history, detailed physical examination and genetic test.